90° bolt-on joint, often used to make additions or alterations to existing structures where a type 101 or similar cannot be fitted. Type 135 is a similar clamp-on fitting. The through tube (horizontal in photo) cannot be joined within the fitting. This fitting comes in one sizes and fits the following pipe sizes
C42 fits a 42.4 mm outside dia pipe and fits a 32 mm nominal bore pipe. D48 - fits a 48.3 mm outside dia pipe and fits a 40 mm nominal bore pipe
The nominal bore of a pipe is its internal dimension.